Hoist piping for deep-sea mineral slurry

ABSTRACT

Pipe sections adapted for constructing into a lengthy fluid circuit for hoisting mineral slurry from a mining plant working a deep ocean bed to a surface ship. Each pipe section possesses termini for facilitating the initial under-water construction of the circuit and strength for supporting the mining plant as it is simultaneously lowered to the bed. A pipe section contains a pump for lifting slurry through its length and a dump-valve for dumping slurry in the event a malfunction occurs in the circuit. A series of buoyancy tanks separated by cushions are disposed along the sides of a pipe section contribute counter-balancing forces that largely neutralize the load that would otherwise accumulate in the circuit. The cushions are adapted to prevent high direct contact pressures between opposing surfaces of adjacent tanks.

United States Patent [19;

Dane, Jr. [4 1 May 29, 1973 s41 HOIST PIPING FOR DEEP-SEA 2,939,860 6/1960 Schramm ..138/D1G. 7 ux MINERAL SLURRY 3,318,327 5/1967 HimesetaL. ..37/D1G. s UX 2,874,722 2/1959 Hamblin ..l 38/lll UX lnvent'orl Ernest Blaney Dane, J 57 Tyler 2,824,520 2/1958 Bartels ..417/424 u'x Road, Belmont, Mass. 02178 [22] Filed: Dec- 28 1970 Primary Examiner-Harvey C. Hornsby Assistant Examiner-W. Scott Carson [21] Appl. 102,034 Attorney-Jack Larsen Related US. Application Data [57] ABSTRACT [62] of 754391 1968 aban' Pipe sections adapted for constructing into a lengthy doned' fluid circuit for hoisting mineral slurry from a mining plant working a deep ocean bed to a surface ship. [52] 0.8. CI. "417/424, 166/6, 302/14, Each pipe Section possesses termini for facilitating the 138/178 302/64 37/1310 8 initial under-water construction of the circuit and [51] Int. Cl. ..Fl6l 9/12, E2lb 7/12 strength for Supporting the mining plant as it is Simu [58] Field of Search ..37/DIG. 8; 138/111, taneously lowered to the A pipe Section contains 138/113 178i 166/5; 175/7; a pump for lifting slurry through its length and a 302/14-16, 64; 415/7; 417/ 424 dump-valve for dumping slurry in the event a malfunction occurs in the circuit. A series of buoyancy tanks References Cited separated by cushions are disposed along the sides of a pipe section contribute counter-balancing forces that UNITED STATES PATENTS largely neutralize the load that would otherwise accu- 3,433,163 3/1969 Sheets et a1 ..417/356X mulate in the circuit. The cushions are adapted to 2,610,028 9/1952 Smith ..138/178 X prevent high direct contact pressures between oppos- 3,548,884 12/1970 Ambrose "138/178 X surfages of adjacent [ank5 3,456,37l 7/l969 Graham et al. ..37/DIG. 8 UX 2,961,711 11/1960 Diedrich et a1. ..138/D1G. 7 UX 9 Claims, 14 Drawing Figures HOIST PIPE SECTION PATENIELHAYZSISH 3,736

sum 1 OF 8 OUTBOUND MINING SYSTEM INVENTOR. ERNEST B. DANE, JR. BY

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BY SESSILE SHIP A? J I. A

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BY HOIST PIPE SECTION wkalLLk-%L ORNE Y PATENTEU M91915 3 ,736,077

SHEET l; UF 8 EMERGENCY DUMP VALVE INVENfO/F ERNEST B. DANE, JR

ATTORNEY PATENTEUHLYZSIUIS 3,73 ,077

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ATTORNEY IIOIST PIPING FOR DEEP-SEA MINERAL SLURRY This application is a division of my copending, but now abandoned, application Ser. No. 754,191, filed Aug. 21, 1968, and subject to a requirement for restriction.

This invention relates generally to fluid conveyors,

- and particularly to pipe sections adapted for the construction of a hoist circuit for lifting ore slurry from a deep sea mining plant.

BACKGROUND OF INVENTION hoisting system that conveys it to ore bins in the surface ship.

The subject of this application is the lengthy hoist system of which the following features are desired. The hoist pipes should be easily and inexpensively transportable to the mining site which may be a considerable distance from port. The sea bed to be mined ordinarily rests at ocean depths presenting a hostile environment to both man and machine. Then, the hoist circuit must be such to permit deployment of the entire system at more favorable ocean depths. Once constructed, the circuit should be capable of transmitting ore slurry processed by the plant without placing excessive loads on the circuit or ship. The circuit should have special provisions for treating malfunctions without requiring recall of the entire mining system, and be capable of withstanding the stresses of its environment and those created by the mining plant.

SUMMARY OF INVENTION In view of the foregoing characteristics desired of a hoist pipe circuit, applicant has, as the principal objects of his invention, to provide sections of pipe that may be assembled into a circuit having the previous stated qualities.

These and other objects are met by buoyant sections of hoist pipe with termini facilitating the serial interconnection of pipes underwater into a circuit. A pipe section contains a pump for lifting slurry through its length and an electrically actuated dump valve controlled from the surface ship for rapidly dumping slurry in the event of a failure in the circuit. A series of buoyancy tanks separated by cushions are located on the sides of the pipe and contribute counter-balancing forces that keep the load of the circuit within tolerable levels. The cushions are adapted to prevent high direct contact pressures between opposing surfaces of adjacent tanks.

DESCRIPTION OF DRAWINGS The above and other features of the invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, of which:

FIG. 1 is a distant vertical view of the mining system in transport to the mining site with the hoist pipe sections in tow.

FIG. 2 is a side cut-away view of the Sessile ship of FIG. 1 in an up-right orientation freed of streamlining,

strengthening and propelling boat sections of FIG. 1 and with a mining plant clamped to its bottom.

FIG. 2A illustrates the bottom dump hatches of ore bins in the bottom of the Sessile ship of FIG. 2.

FIG. 3 is a partial cross-sectional side view of two joined pipe sections of FIG. 1 illustrating the principal features of their junction.

FIGS. 3A, 3B and 3C are top cross-sectional views of a pipe of FIG. 3 along cutting planes A-A, B-B and CC, respectively, while FIG. 3D illustrates the spherical buoyancy tanks used in pipes disposed in the lower deep-sea environment.

FIGS. 4 and 4A are side and vertical views, respectively, of the dump valve in a pipe section of FIG. 3.

FIG. 5 is a detailed side view of the secured junction of FIG. 3.

FIG. 6 is a side view of the Manbot used to construct the hoist pipe circuit and its operation in securing the pipe junctions of FIGS. 3 and 5.

FIG. 7 illustrates the hauling down of the pipe sections of FIG. 1 in the assembly of the hoist pipe circuit.

FIG. 8 illustrates the terminal junction between the hoist pipe circuit and the Sessile ship of FIG. 3.

PREFERRED EMBODIMENT Shown in FIG. 1 is a distant vertical view of the forementioned mining system as it would appear being transported to a distant deep sea mining site. The referenced surface ship is a Sessile ship disposed in a horizontal orientation and equipped with streamlining, strengthening and propelling boat sections 20, 40 and 60, respectively, which are detachable. Sessile ship 100 holds mining plant 300 clamped to the normal bottom of the ship. The buoyant hoist pipe sections 200, which are the subject of this application, are towed to the mining site by tug 85.

Once over the selected mining site, Sessile ship 100 is freed of sections 20, 40 and 60 and is raised upright. The manner of detaching the sections and erecting the ship along the vertical is discussed in the parent application. FIG. 2 shows the ship in an upright orientation disposed to serve as a surface vessel for receiving and storing ore when it is eventually mined by plant 300 and conveyed to the ship by the hoist circuit to be constructed. Buoyant hoist pipe sections 200 are shown floating nearby held on station by motored launch 10.

I-Ioist pipe sections 200 serve a dual purpose in the mining venture. They are used during the construction of the hoist pipe circuit to lower mining plant 300 to the ocean floor, and to raise the plant during disassembly of the circuit upon completion of the mining operation. Mining depths may be in the order of 5,000 meters. The length of the pipe sections is governed by practical construction limitations, however, 300 meter lengths offer one acceptable dimension. In this event, about 17 sections are required to cover ocean depths contemplated. The pipe sections of the circuit are designed also to lift ore slurry at a rate specified by the design of the mining system. For purposes of the preferred embodiment of the system, as described in the parent application, this rate is in the order of 500 metric tons of ore slurry per hour. The teachings of the invention apply to other parameters of length and lift rate.

The Sessile Ship Sessile ship is instrumental in the performance of cables on the pipe sections to operate the mining plant on the ocean bed. The ship also serves as the receiving terminal of the hoist circuit. Therefore, to support a detailed description of the hoist pipe circuit and its sections and the invention in its preferred embodiment, features of the ship are next outlined.

As shown in FIG. 2, the Sessile ship contains multiple levels of decks 125a through 125g and ore bins 175. Decks 125a through 1250 have single and double drum winches 127, 129, 131' and 133', 137', respectively, holding cables 127, 131, 129, 133, 137 extending down central well 121, or out hatchway 143 and through a series of snatch blocks 147, some of the latter resting on flat landing 149. Cable 127 is a sheet cable of lightweight electrical conductors for carrying power and control signals from a control room on deck 125e to miner 300 and pipes 200. Appropriate lines of cable 127 are connected to the various terminals of miner 300 and pipes 200 during construction of the hoist circuit. Cable 131 has a pair of electrical wires that convey temporary power for initially operating the two top winches of the first pipe section. Cable 129 is an elevator cable for manipulating the position of a manned submersible as will be described. Cables 133 and 137 are hoist cables each havingtwo lines with a load capacity greater than the weight of miner 300, which may be in the order of 100 tons. Two lines of cable 133 are attached to eyelets at the top of outlet pipe 305 of miner 300, and each pays out from one of the interconnected drums of winch 133. A line of cable 137 from coupled drums 137 is attached to each of folding joints 346 of the miners arms. Hoist cables 133 and 137 serve to lower the miner and forming hoist circuit.

Decks 125d contain personnel facilities and space for a number of functions in support of mining operations. Fuel cells 125f' on deck 125f supply electrical power to the system and to drive propellers 181 to station the ship. Ballast tanks 155b on deck 125g cooperate with blow tanks 155a to perform ballasting action. Circular pipe 165 is designed to receive mined ore from the mining plant 300 after it starts mining the ocean floor. Ore slurry from pipe 165 is released into funnel shaped bins 175. As shown in FIG. 2A, a typical bin is equipped with dump hatches 177 (shown open) and pumping apparatus 187 and 189 between feedline 183 and external discharge pipe 190.

The Hoist Pipe Circuit The hoist pipe circuit used to transfer ore from central miner 300 to Sessile ship 100 is constructed from the several hoist pipe sections 200 of FIGS. 1 and 2 towed to the mining site. The pipes are serially connected between the miner and pipe 165 in ore bin 175. Each pipe section includes a pump for raising the slurry through its length and an emergency valve to permit rapid dumping of the slurry in the event there is a serious failure in the system. The pipes are made of strong buoyant material and further equipped with buoyancy tanks. They are designed so that the resulting buoyancy is sufficient to support most of the total weight of the loaded pipe section including that of its pump, pipe and about 8 tons of ore slurry. The pipes have sufficient radial strength to withstand the internal pressure of the slurry. They are also provided with enough longitudinal reinforcement to withstand both the stresses caused by subsurface sea forces and to support the weight of the central miner. The pipes are used to transport the miner between the Sessile ship and sea bottom both during the initial deployment of the system and upon termination of the mining operation. The pipes are also equipped with water-tight electrical connectors that receive lines in cable system 127 supplying electrical power for the pumps and auxiliary equipment. One pair of power lines is assigned to each pipe and the performance of the corresponding pump is monitored by measuring its consumed power.

Pipe Sections The principal features of each pipe section 200 are illustrated in FIGS. 3-6. FIG. 3 shows two pipe sections 200' and 200 as they appear after being joined in the assembly of the pipe circuit. The top of pipe section 200 is joined to a succeeding pipe 200 by toggle ring binder 205 and other fastenings to be later described in conjunction with FIG. 5. Pipe section 200" is representative of the lower portion of each pipe section. It comprises plastic pipe 201 having an internal diameter of about 40 cm except at pump-portion 220 where it widens out to a diameter of 3 to 4 meters. Located above pump portion 220 is about meters in lengthof flotation gear in the form of hollow tanks 240. Above the tanks each pipe section 200 assumes the form of simple pipe 200. I:

Since it is difficult to extrude pipes in 300 meter sections at onetime, each pipe section is fabricated on shore in parts that are subsequently molded or otherwise fastened together lengthwise. Pipe 201 is made of strong, non-porous and naturally buoyant material of low specific gravity having a compressibility approximating or preferably less than the compressibility of sea water. These properties are designed to prevent the pipes from sinking gradually when subject to the sea pressures along the length of the circuit. Polypropylene and polyethylene plastics possess the sought characteristics. Pipe walls are about 2.5 cm thick and are internally lined with material 202 that resists the abrasion of moving slurry, for example, a rubber lining of about 0.5 cm thickness. Each pipe is equipped with four or more I-bars 203 that improve the tensile strength of the pipe which supports the miner 300 as it is lowered from the ship according to a procedure to be described shortly. The I-bars are plastic potted fiberglass and secured to the pipe with the aid of wrapping straps around the outside of each pipe. The rubber lining and I-bars are shown in FIGS. 3A,3B and 3C which are crosssectional views of the areas cut by planes AA, B-B and C--C, respectively.

Pump section 220 houses a pump with motor 224 within casing 225 capable of pumping 500 metric tons of slurry per hour at a moderate head. Motor 224 is coupled downward to rotor 227 having many vanes located at the bottom of pump section 220. Pumps for carrying this load are well within the pump art. A modified version of the radial flow type used on hydraulic dredges is employed in the pump. The modification resides in building an upward curvature in the stator guide vanes.

In particular, in a conventional rotary pump, the rotor vanes impart tangential motion of the pumped fluid. The fluid is collected by a stator surrounding the rotor and is redirected out the pumps discharge terminal. In the modified pump shown in FIGS. 3 and 3B, stator guide vanes 226 are mounted on the inside wall of pump section 220. The surfaces at the input side of guide vanes 226 are shaped to receive the tangential fiow while the surfaces at the output side are codirectional with the axis of the rotor or the axis of the pipe. The intervening vane surfaces have a gradual twist that provides a smooth directional transition. Stator vanes 226 thus transform ore slurry leaving rotor vanes 227 from a tangential fiow into an axial flow upward through the spacing between casing 225 and the internal wall of pump section 220. To reduce wear, the rotor and stator vanes and casing 225 are rubber lined.

To reduce brush wear, pump motors are of the a-c type. They are three phase excited. Cable system 127, shown in FIGS. 3A, 3B and 3C is sheet cable which is added to the pipe section. The individual lines of cable 127 tap off the sheet at points along its length and couple in two phases of the three phase supply. Two such tap-off lines 229 are illustrated in FIG. 4 to which reference is shortly made. Power is coupled to the motor stator through some of the rubber covered stator vanes 226 of the pump. Plate 231 mounted on the pump section provides a third terminal. It has enough area to provide a good electrical circuit thru the seawater between it and the ships metal structure which serves as the other ground terminal. For maximum efficiency, rotor vanes 227 are run at about 960 rpm. For operating minimum weight motors at maximum efficiency, high speeds of about 1,700 rpm are preferred. To gain this advantage, the coupling between rotor vanes 227 and the pump motor has a single step reduction gear to reduce the speed of the former.

Still referring to FIG. 3, just above pump section 220 is about I00 meters of serially arranged tanks 240 affixed to the outside of pipe 201. These supply about three-fourths of the buoyancy needed to support section filled with ore slurry. Tanks used in the environment of great depth, say below 3,000 meters, require greater strength'than ones used at lesser depths. For lesser depths, tanks are cylindrical with hemispherical tops and bottoms as in FIGS. 3 and 3A, and are made of fiberglass, plastic or aluminum. At greater depths tanks 240 of FIG. 3D, are preferably the more expensive hollow glass spheres. Tanks 240 and 240 are filled with air or another gas. The tanks are enclosed by a thick plastic cover or tube 239 that makes them easier to tow on the surface and protects them from abrasion during construction of the pipe circuit to be described subsequently. The tank floatation gear is further secured to pipes 201 by bands that extend around both tanks and pipes.

The tanks are serially disposed along the length of a pipe with collar-like cushions 237 interposed between the opposing curved surfaces of adjacent tanks. Cushions 237 are of solid propylene reinforced with fiberglass and are designed to prevent high direct contact pressures from occuring between the curved surfaces of the tanks. As is seen in FIGS. 3 and 3D, a pair of cables is linked between each of padded collars 237 and the heavy pump section 220 to distribute the load between tanks, preferably so that they each support about the same weight.

Near the bottom of pump section 220 is emergency dump valve 250. Valve 250 provides an exit by-passing the pump's rotor and stator for releasing the column of ore slurry in the event of an emergency and also affords access for repairing the pump in the event it is necessary. Valve 250 is-positioned to allow the pipe to release most if not all of its slurry without backing up in the pump. FIG. 4 offers a cut-away side view with details of valve 250 shown in a closed condition, while FIG. 4A is a top view of the valve when opened. Referring to FIG. 4, dump valve 250 comprises door 241 mounted on hinge 242. Door 241 is closed by the pull of chain 243 when winch 245 is energized. When door 241 is shut, solenoid catch 247 is activated causing it to force up against the door, locking it in place. Winch 245 is then reversed allowing slack in chain 243, this state being shown in FIG. 4. Commands for operating the mechanisms are provided by lines 229 of cable system 127 coupled into pump section 220 by connectors 229. Lines 229 carry power to both the pump motor and solenoid catch 247. In the event the pump is shut down due to a power failure or intentionally because of a malfunction, catch 247 is automatically released. Door 241 swings open by the force of the slurry to the position of FIG. 4A and the ore is dumped. Lines 229 also include a line for controlling winch 245 so that it takes up or releases chain 243 when desired.

FIGS. 4 and 4A also illustrate other features of the area near pump section 220. Rubber lining 202 is shown covering the internal wall of pipe 201 and casing 225 of the pump motor. One of the series of straps 249 wraps around longitudinally extending strengthening I-bars 203 and pipe 201 holding the former in place. One of the series of binding cables 251 holds those lines of cable system 127 continuing down to a lower pipe section. Top view 4A shows stator guide vanes 226 fixed to the inside wall of the pump section.

Connectors, such as connectors 220', employed to connect cable system 127 to various points in the mining system are oil filled and of the kind typically used to couple power into submarines or other submersibles. They point downward and have an oil filled chamber that insulates the internal sockets from sea water. A tape seal across the mouth of the chamber helps to retain oil and exclude sea water. When the connector is ready to receive its power cable, the tape seal is removed and pins of the cable are mated with the sockets. To resist corrosion, cable pins and connector sockets are made of solid copper or copper plated. Care is exercised to prevent the pins and sockets from contacting the sea water. Once the connection is made, the junction is sealed by rubber tape or other suitable material and secured by a strong spring fixture to prevent it from being shaken free by pump or other vibration.

FIG. 5 is a detailed view of the junction of pipe section 200 and 200" of FIG. 3. It is recalled that the junction is representative of the two ends of each pipe section. To stabilize their registration, the ends of each pipe section are flanged. Strengthening I-bars terminate into eye splices 204, both being secured by wrapping straps 249. Eye splices 204 are located at both ends of a pipe and have extra holes 204a for receiving hoisting or haul-down cables. The bottom of each pipe section is originally equipped with pelican hooks 207 with safety ring 2070, ring binder 205 held by chains 205a while the eye splice of the top of each pipe is originally provided with shackle 207e. The nature and functioning of each of these components is next discussed in conjunction with a description on how the joint is made.

The pipes are joined by aligning their ends so that the flanges are in smooth registration and both sets of eye splices 204 are mutually opposing. The alignment is worked by the manned assembler or Manbot of FIG. 6 to be described shortly. Ring binder 205 comes already attached to the bottom end of each pipe section by chains 205a. It is fitted over the joint crosswise. The ring binder is equipped with toggle levers 205b that, when folded back, clamp the ring in place. Pelican hooks 207 connected to eye splices 204 abutting the bottom end of each pipe section are then secured. Hook 207 has ring 207a, and a member 207b joined at one end to rotatable arm 207d by pin 207C. The opposite end of member 207b has jaws that are bolted to one end of a short turnbuckle 209. Each arm 207d is arranged to fit through shackle 207e fixed to an eye splice at the top of a lower pipe 200 and to fold back on member 207b. Turnbuckle 209 is incorporated between eye splices at the bottom end of each I-bar 203 and the pelican hooks abutting the bottom end of a pipe. Once arm 207d of each pelican hook is fitted through its corresponding shackle 207e, folded back to overlap its member 2071) and locked by safety ring 207a, the junction is secured by the action of the pelican hooks. Further adjustment and tightening of the clamping action of the hooks is provided by the turnbuckle 209 associated with each hook.

Each of the pipe sections is as above described except the first pipe section that is connected directly to the miner. It incorporates one or a pair of winches near its top that are linked to the folded joints 346 of the miners arms. They allow controlled tension to be applied to the arms when the arms are extended or folded-up. The winch is illustrated in later FIG. 6 where the pipe sections are assumed to be the first and second.

The winch has drum 339 holding cables 341 and 341 for attachment to the arms 346 and mounted on frame 337. Drum 339 is geared to motor 335. Motor 335 is temporarily energized by cable 131 but later by sheet cable 127 after the latter is linked with the pipe.

The Manbot Assembler As is apparent, the central miner and the pipe sections are heavy, bulky and unwieldy. However, all the parts are deep below the action of waves, in quiet water, which should more than balance the difficulty of under water work. Moreover, there are only 17 joints to be made, considerably less than where the hoist circuit is composed of shorter sections. Some mechanical means is therefore necessary for assembling these components into a working system. For this purpose, the mining system employs one or more manned submersible machines, here termed a Manbot, which is a variant of the kind described in The Deep Submersible, by Richard D. Terry, published by Weston Periodicals Co. (I966), at page 169. The Manbot, which is well within the submersible art to manufacture, comprises a manned water-tight chamber capable of descending to depths of at least 400 meters.

Such a Manbot is shown in FIG. 6 making the junction between the two pipe sections 200' and 200" of FIGS. 3 and 6. The Manbot comprises water-tight chamber 250 carrying an operator in a shirt sleeve environment. It is attached by suspension member 251 to the ship's elevator cable 129. The Manbot is equipped by telephone to control room l25e and is raised and lowered by elevator winch 129 of FIG.

upon the operators instructions. Ventilation is supplied by inlet air hose 252 in entrance hatch 259 and by exhaust hose 254. Electrical power is furnished through cable 255. The Manbot has a pair of anchoring clasps 262 for anchoring it to positions along the pipe section. The bold is fitted by saddles 261 on the inside of clasps 262. The clasps are opened and closed by operation of cylinders 264. A similar member, upper clasp 272, is extended upward by support 268. Clasp 272 is opened and closed by operation of cylinder 271. The height and angular position of upper clasp 272 is variable so that it can accurately line up upper pipe section 200". Angular adjustment cylinder 267, which is connected by a rod to support 268, controls the angular position of clasp 272. Height adjustment cylinder 269 linked to clasp 272 by support 268 controls its height. One or more cylinder operated manipulator arms 275 are incorporated to perform a number of functions. In FIG. 5, one is shown closing a rotatable arm 207d of a pelican hook. They are also used to hook and unhook cables, insert clevis pins and to tighten bolts. Components for these latter operations are obtained from tool crib 273 mounted on the middle clasp and within easy reach of arms 275. High pressure hydraulic fluid to operate the equipment is supplied by hoses coupled to the surface ship or by pumps on the Manbot.

To enable the operator to see the working area, the Manbot has a number of side portholes 253 and a few floodlights 257. At the bottom of chamber 250 is a pair of interconnected drums 280 each containing over 400 meters of haul down cable 280 strong enough to pull approximately 10 tons of load. Cables 280 are used to haul down the floating hoist pipe sections 200 of FIG. 2 in the assembly of the hoist pipe circuit.

By coordinated action of clasps 262 and 272, the Manbot is able to climb up and down a hoist pipe section or any other structure which it may grasp. Clasps 262 give it an anchoring support while clasp 272 permits it to lift or lower itself along the structure.

Lowering the Miner and Pipe Sections Referring again to FIG. 2, hoist cables 133 and 137 are appropriately connected to miner 300 and the system is prepared for deployment. Pipe sections 200 and motored launch 10 are brought in the proximity of the ship. An endless wire 157 having a hook-ring attached is run between the launch and ship. The wire extends down central well 121, up the side of the ship to the launch, and from the launch back to well 121 through a hatch opening made by the removal of plate 143. The wire is mounted on pulleys so that the hook-ring may be reeled in a closed loop between the ship and the launch.

The lowering procedure begins by releasing the clamps holding miner 300 so it is totally carried by cables 133 and 137. Both winches 133 and 137 are operated to pay out cable at the same rate so that the miner descends levelly until it reaches a depth of a little more than one pipe length, say about 400 meters. The Manbot which is connected to cable 129 may clamp itself to outlet pipe 305 and descend with the miner or be lowered after the miner reaches its station. In either event, before descending, the Manbots haul-down cables 280 are hooked to the ring on the endless wire. As it descends, the Manbot pays out cable 280. When the Manbot is firmly clamped to outlet pipe 305 of the miner, it informs the ship that it is ready to haul down the first hoist pipe section. Personnel in launch 10 draw on the endless wire until they receive the ends of cables 280 at which time they are connected to eye splices 204 at the bottom of the first pipe section. A plastic guard is mounted around the bottom of the first pipe to protect it from possible collision with the side of ships bottom 180.

The Manbot slowly'hauls the first pipe section down by means of winch 280'. Launch 10 guides the surfaced portion of the pipe so the pipe does not get too close to the ship. The haul down continues until the end of the pipe is about 5 cm from the top of outlet pipe 305. The operator grasps the pipe section with upper clasp 272 of FIG. 5. The guard is removed by manipulator arm 275. Using the angular and vertical flexibility of clasp 272, the operator draws the first pipe section into exact rotational and coaxial alignment with the top of outlet pipe 305. When the eyelets and eye splices are opposing, he draws the pipe section down so it sits on the flanged outlet pipe. The operator installs ring binder 205, which is hanging on chains 205a, around the registering flanges and clamps it tight. The operator then takes pelican hooks 207, already hanging from the bottom eye splices 204 of the pipe, and sets them up tight through shackles 207e thereafter dropping safety ring 207a. Four pelican hooks are applied to the junction in the manner shown in FIGS. 4 and 5.

For the time being, lines 133 remain attached to outlet pipe 305. The Manbot is then raised by elevator cable 129, hooks its haul-down cables 280 to endless wire 157, and returns to the top of the first pipe section. The ships crew links cables 280 to the two lines of temporary cable 131 and the Manbot draws them down and connects one to each top winch of the first pipe section. The operator in the Manbot then asks for the ship to activate the two top winches of the first pipe section to pay out line with power applied through cable 131. Climbing up and down the pipe and the arms of the miner, the operator attaches one of the winch lines to each double joint 346 of the arms and then instructs the ship to draw the top winch line taut. The Manbot then brakes the two top winches. Cables 137, which are originally coupled to joints 346, are slacked, freed and drawn back by winches 137'.

With the aid of a scuba diver, lines 137 are drawn through a snatch block 147 and are led down the side of the ship along the course of dashed line 137 of FIG. 2. The Manbot returns toward the ship via line 129 and again attaches haul down cables 280 to the endless wire. It then clamps itself to the top of the first pipe section. Cables 280 are hauled up on the outboard side by the endless wire and each end is fastened to one of lines 137. The operator then hauls down lines 137 and attaches them to top eye splices 204 of the first pipe section. Upon instructions from the operator, winches 137 are set up gently on their lines and set their brakes while winches 133 slack off lines 133. The whole weight of the miner transfers to outboard lines 137. Simultaneously, ballast tanks 155b on the opposite side of the ship take on enough water to counterbalance the off-center weight of miner 300. The Manbot descends to the miner and detaches lines 133 from outlet pipe 305. Freed lines 133 are retrieved by the ship and led over the side through another snatch block 147 by the same procedure used in conjunction with lines 137. Lines 133 now follow dashed line 133 of FIG. 2 down the side of the ship.

The Manbot is returned up elevator shaft 121 and then lowered over the outboard side through hatchway 143. With the aid of scuba divers, elevator cable 129 is guided through a snatch block 147 along a course shown in dash, and in proximity with hoist cables 133 and 137. The operator connects haul-down cables 280 to endless wire 157 and pays out cable 280 while it is lowered to outlet pipe 305 of miner 300. The Manbot clamps itself to pipe 305.

Electrical cable 127 is led out hatchway 143 and through a snatch block 147, as illustrated by the dash line of FIG. 2. It is linked-up with haul-down cable 280 attached to endless wire 157. Drum 129 is slacked off and the Manbot is instructed to haul down cable 127 and connect it up with electrical apparatus on miner 300 and in the first pipe section. With the aid of clasps 272 and 262 of FIG. 5, the Manbot maneuvers and fastens lines of cable 127 to connectors of electrical apparatus in the body and arms of the miner, such as motor drives for the tractors and control and monitoring equipment, and finally to the pump section and the two top winches of the first pipe section. With the aid of color codes and connector shapes, the terminals of cable 127 are coupled to the proper connectors of the miner and first pipe section. Wrapping straps are applied along the first pipe section to secure cable 127. Temporary electrical cables 131 are replaced by lines of cable 127 at the top winches and cables 131 are retrieved by the ship.

The Manbot ascends, connects its cables 280 to the endless wire and returns to the top of the first hoist pipe section where it anchors itself. Cables 280 are connected to the bottom eye splices 204 of the second pipe section. Lines 137 are lowered one pipe length, the Manbot paying out cable 280 as it rides down with the pipe. The Manbot at the construction depth then proceeds to haul down second pipe section. The descent of the second pipe section and other principal aspects of the operation are illustrated in FIG. 6 where electrical cables 127 are omitted for clarity. FIG. 6, not being drawn to scale, does not show the ship, miner, pipes and Manbot in proper proportion.

The second pipe section is pulled-down until its lower end is about five centimeters above the top of the first pipe section. The operator then grasps the second pipe with upper clasp 272 of FIG. 5 and aligns its bottom splices 204 with those at the top of the first pipe section. The second pipe is drawn into registration and the junction is secured by application of ring binder 205 and pelican hooks, in accordance with FIGS. 4 and 5. After making electrical connections between lines of electrical cable 127 and corresponding electrical terminals on the second pipe, the Manbot is raised by elevator cable 129 toward the endless wire. The Manbot attaches haul-down cable 280 to the endless wire, whereafter previously freed hoist cable 133 is linked with cable 280 at the ocean surface. Releasing cable 280, the Manbot descends to the top of the second pipe sectionwhere it anchors itself and next draws cable 133 down with winch 280. Cables 133 are then joined to eye splices 204 at the top of the second pipe section.

The Manbot is next lowered by elevator cable 129 to the top of the first hoist pipe section. Upon instructions from the operator, winches 133 set-up gently on cables 133 and winch 133' is braked, while winches 137' slacken cable 137. The weight of the miner and the interconnected pipe section is thus transferred from cable 137 to cable 133. The Manbot detaches cable 137 from the top eye splices of the first pipe section. The Manbot is then raised by elevator cable 129 and again connects haul-down cable 280 to the endless wire. The Manbot then returns to a station on the top of the second pipe section. Winch 133 lowers the miner to a third depth, the Manbot riding on the top of the second pipe being again carried down to the construction depth while paying out cable 280 on the way down. Cable 280 is then attached to the bottom eye splices 204 of the third pipe section and the pipe is prepared for being hauled down by the Manbot for connection with the top of the second pipe section in accordance with FIG. 6.

The above sequence of operations performed by the Manbot is repeated until the miner reaches the ocean floor. Hoist cables 137 are used to secure the tops of odd numbered pipe sections while even numbered sections are hauled down and linked therewith by the Manbot. Likewise, hoist cables 133 are utilized to hold the tops of even numbered pipe sections, while odd numbered sections are hauled down and connected-up therewith. More generally, miner 300 is lowered to the kth depth, where k is an integer (k=l,2,...n), and the kth pipe section is hauled down by the Manbot clamped to the top of the (k-l )th pipe section. The junction between the two sections is secured in accordance with FIGS. 4 and 5. After the junction is secured, the Manbot connects corresponding lines of electrical cable 127 to electrical apparatus in each pipe.- The Manbot is raised by elevator cable 129 to attach haul down cable 280 to the free hoist cable of cables 133 and 137 so that it may transfer at the top of the kth pipe section. The alternative hoist cable is freed and the Manbot then connects cable 280 to the endless wire for subsequent transfer to the (k+l )th pipe section. Subsequently, the Manbot stations itself on the top of the kth pipe section whereupon the miner is lowered to the (k+lth depth. The Manbot rides down with the kth pipe section to the construction depth where it becomes stationed for hauling down the (k+l )th pipe section.

The miner eventually reaches the ocean floor and the nth pipe section is hauled down and joined with the (n-l )th section. The nth pipe section may be shorter than the other sections in order to locate a circuit terminal at approximately the same subsurface level as the ore bins at the bottom of the Sessile ship. Thus, the collection of pipes of FIG. 1 towed to the site may include some pipes with the shorter than the standard length, here 300 meters, to provide a satisfactory termination of the hoist circuit. The n joined pipe sections then form a hoist pipe circuit spanning the distance between the ocean bed and a point just below the surface where a terminal next to be described is applied between the circuit and Sessile ship 100. All electrical power and control circuits between Sessile ship 100, miner 300 and the respective pipe sections are made by sheet cable 127 of FIGS. 3A, 3B, 3C affixed to each pipe.

Reference is now made to FIG. 7. After the last pipe section, the nth, has been connected, subsurface float 290 is partially flooded, conveyed down to the last pipe section and connected therewith. Float 290 contains one end of flexible pipe 295 that registers with the last pipe. The junction is similarly secured by pelican hooks and a ring binder. Flexible pipe 295 is connected to pipe 165 disposed over ore bins 175. Float 290 contains ballast tanks, pumps powered by a line from ship 100, batteries and a sonar transponder. The ballast tanks are pumped out to give float 290 a buoyancy slightly more than the uncompensated weight of the hoist pipe circuit. It is recalled that buoyancy tanks 240 provide an upward force of about three-fourths the weight of each pipe section when loaded with ore. For example, assumingeach pipe section has a capacity of eight tons of ore, the section is 5 tons light when empty and 3 tons heavy when filled. For neutral buoyancy in the hoist pipe circuit loaded with ore, float 290 provides a buoyant force of l7 3 tons, or 51 tons where 17 sections are used. I

Float 290 is linked with small surface buoy 294 containing both radio tracking equipment and flashing lights. Power for these is obtained from batteries in the float. Buoy 294 is small enough to offer little drag to the pipe circuit even in a typhoon. In the event of a serious storm, the ship may be detached from the circuit and driven to a safe location, and later return by tracking the buoy. The sonar transponder in float 290 serves as a back-up beacon in the event buoy 294 breaks away. Float 290 is sufficiently below the surface to be unaffected by storms.

Although a preferred embodiment for the sections of hoist pipe and circuit have been provided, variations of the principles disclosed are apparent that fall within the spirit of the invention. For example, the physical dimensions of the pipe sections are merely illustrative. To

cover such variations within the spirit of the invention,

it is next defined in the appended claims.

Iclaim:

l. A section of hoist pipe for interconnecting with second and third pipe sections in the construction of a hoist circuit for lifting ore slurry from a deep sea bed, comprising:

a pipe of strong solid material, said material having a compressibility and a specific gravity both less than for sea water, having an internal lining resistant to slurry abrasion, an outer surface, first and second ends with means for engaging said ends with said second and third pipe sections, respectively, said pipe having a pump portion incorporating a pump for lifting slurry along the length of said section, at the lower end of said section,

a plurality of tanks serially arranged along the length of said outer surface above said pump portion, with opposing surfaces of adjacent tanks separated by cushions, and at least one line between said pump portion and each of said cushions for distributing the load between said tanks.

2. A section of pipe as set out in claim 1 wherein said internal lining is of rubber.

3. A pipe section as defined in claim 2 further including a dump valve located under said pump adapted to open outward and offer an emergency exit for said slurry, bypassing the" pump. i Y

4. A pipe section as set forth in claim 3 wherein said engaging means at said second end of said pipe includes a first set of eye spliceswith shackles for engaging with:' i

pelican hooks, said engaging means located at said first end of said pipe comprises a plurality of pelican hooks, and said pipe has a plurality of l-bars running along its" 5. A section of pipe as defined by claim 1 wherein said tanks are spherical glass balls.

6. A section as defined by claim 1 wherein said material is substantially polypropylene.

7. A section as defined by claim 1 wherein said material is substantially polyethylene.

8. A section of hoist pipe for interconnecting with second and third pipe sections in the formation of a hoist pipe circuit for lifting ore slurry from a deep sea bed, comprising;

a polypropylene pipe having a rubber lined internal surface, first and second flanged ends with means for engaging with said second and third pipe sections, respectively, and said pipe having a pump portion housing a pump for lifting slurry,

a plurality of gas filled tanks arranged serially on the outside of said pipe with opposing surfaces of adjacent tanks separated by a cushion and said cushions each connected by a line to points on said pump portion thereby distributing the load between said tanks,

a dump valve located under said pump adapted to open outward and offer an emergency exit for said slurry, and

a plurality of I-bars running along the length of said pipe with the ends of said lbars terminating into said engaging means located at said first and second ends of said pipe.

9. A section of hoist pipe as set forth in claim 8 wherein the inside of the pump section has stator vanes and said pump is of the rotary type having rotor vanes, said rotor vanes adapted to rotate about the axis of the pipe and produce tangential flow in said slurry, and said stator vanes are twisted toward said axis so as to transform said tangential flow into axial flow along said pipe. 

1. A section of hoist pipe for interconnecting with second and third pipe sections in the construction of a hoist circuit for lifting ore slurry from a deep sea bed, comprising: a pipe of strong solid material, said material having a compressibility and a specific gravity both less than for sea water, having an internal lining resistant to slurry abrasion, an outer surface, first and second ends with means for engaging said ends with said second and third pipe sections, respectively, said pipe having a pump portion incorporating a pump for lifting slurry along the length of said section, at the lower end of said section, a plurality of tanks serially arranged along the length of said outer surface above said pump portion, with opposing surfaces of adjacent tanks separated by cushions, and at least one line between said pump portion and each of said cushions for distributing the load between said tanks.
 2. A section of pipe as set out in claim 1 wherein said internal lining is of rubber.
 3. A pipe section as defined in claim 2 further including a dump valve located under said pump adapted to open outward and offer an emergency exit for said slurry, bypassing the pump.
 4. A pipe section as set forth in claim 3 wherein said engaging means at said second end of said pipe includes a first set of eye splices with shackles for engaging with pelican hooks, said engaging means located at said first end of said pipe comprises a plurality of pelican hooks, and said pipe has a plurality of I-bars running along its length with first ends of said I-bars terminating into said first set of eye splices and the second ends of said I-bars terminating into turNbuckles connected with said pelican hooks of said first end of said pipe.
 5. A section of pipe as defined by claim 1 wherein said tanks are spherical glass balls.
 6. A section as defined by claim 1 wherein said material is substantially polypropylene.
 7. A section as defined by claim 1 wherein said material is substantially polyethylene.
 8. A section of hoist pipe for interconnecting with second and third pipe sections in the formation of a hoist pipe circuit for lifting ore slurry from a deep sea bed, comprising; a polypropylene pipe having a rubber lined internal surface, first and second flanged ends with means for engaging with said second and third pipe sections, respectively, and said pipe having a pump portion housing a pump for lifting slurry, a plurality of gas filled tanks arranged serially on the outside of said pipe with opposing surfaces of adjacent tanks separated by a cushion and said cushions each connected by a line to points on said pump portion thereby distributing the load between said tanks, a dump valve located under said pump adapted to open outward and offer an emergency exit for said slurry, and a plurality of I-bars running along the length of said pipe with the ends of said I-bars terminating into said engaging means located at said first and second ends of said pipe.
 9. A section of hoist pipe as set forth in claim 8 wherein the inside of the pump section has stator vanes and said pump is of the rotary type having rotor vanes, said rotor vanes adapted to rotate about the axis of the pipe and produce tangential flow in said slurry, and said stator vanes are twisted toward said axis so as to transform said tangential flow into axial flow along said pipe. 